The Latest from the NanoCenter

Landmark Study on Nanomaterials and the Environment

June 22, 2009

Too tiny to see or touch, manmade nanoparticles are increasingly becoming a byproduct of industry and chemical and pharmaceutical technology.

But once these super small materials enter the water supply, do they reach coastal areas and enter marshes and tidal zones, the complex environments where shellfish and finfish grow?

Researchers at the University of South Carolina’s Nanocenter, working with scientists at the National Oceanic and Atmospheric Administration in Charleston, examined whether gold nanorods could readily pass from water to the marine food web.

Their findings, published online at Nature Nanotechnology, suggest that nanoparticles move easily into the marine food web and are absorbed in grasses, trapped in biofilms and consumed by filter feeders, such as clams.

“This is the first study to report on the fate of gold nanoparticles in a complex ecosystem containing sediments, biofilms, grasses, microscopic organisms, filter feeders and omnivores,” said environmental chemist Dr. John L. Ferry of the University of South Carolina.

The gold nanorods were used in the study because of their ability to be traced, he said.

For the experiment, scientists at NOAA’s Coastal Center for Environmental Health and Biomolecular Research created three estuarine mesocosms, experimental enclosures replicating a coastal ecosystem. In developing the coastal “labs,” NOAA scientists constructed a tidal marsh creek, containing natural, unfiltered water from Wadmalaw Island; planted Spartina grass in sedimnents; and added clams, mud snails and grass shrimp. The gold nanorods were synthesized by researchers at USC and introduced into the ecosystems. At the end of the experiment, the USC team developed the techniques necessary to measure the fate of the nanoparticles and found that clams and biofilms accumulated the most.

“As the first experiment of its kind, we really didn’t know what to expect,” said Dr. Geoff Scott, (Director of Center for Coastal Environmental Health and Biomolecular Research

NOAA/NOS), who collaborated with Dr. Michael Fulton, (Estuaries and Land Use Acting Branch Chief, Center for Coastal Environmental Health and Biomolecular research/NOAA) . “This study enabled us to understand how these nanomaterials were transported through the ecosystem.”

The research has implications for all coastal environments and will provide a baseline for future studies on the environmental impact of nanomaterials, Scott said.

The study is significant because it shows that manmade nanoparticles can enter the estuarine food and ultimately could find their way into the shellfish and fish that humans eat, said Ferry.

“This study is a road map for where we go next,” he said. “We did not look at what happens ‘up the food chain.’ ”

“This landmark study points towards things to come in the near future”, say Tom Vogt, Director of the NanoCenter at the University of South Carolina, “when we will enlarge our national and international R&D footprint even more by developing the recently endowed Center of Economic Excellence for Nanoenvironmental Research and Risk Assessment.”